gen 2 mps3 exhaust questions
Hi guys, just bought a second hand gen2 2010 mps 3 and love it. Cat drives good but noticed 1st and 2nd gear seems sluggish. The car seems to have an aftermarket dump pipe, after market front pipe but standard rear muffler and also has a CEL reporting p0421. Car is not missing but thought I would ask you experts for advice, is there a way way to fix the CEL, should I change the rear muffler as it might be causing loss of power or replace the whole exhaust back to stock.. live in Sydney so if there are any kind people that could point me in the right direction it would be appreciated as I'm not sure how the car is suppose to drive as it was the only one I have ever driven...thanks in advance...